Seat armrest unit



FIG. 1 is a perspective view of the seat armrest unit, showing our new design;

FIG. 2 is a side elevational view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof; and,

FIG. 5 is a top view thereof.

The broken line showing the seat unit to which the seat armrest unit is attached in FIGS. 1-5 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a seat armrest unit, as shown and described. 